Watch this short video on how to navigate SIS.
This is a Chrome issue and not something that can be fixed in SIS. You should still be able to use your mouse wheel or track pad to move down the page. You can also use another browser, such as Firefox.
If you're using a Mac, you can change your settings to always show the scroll bar. Go to System Preferences > General > Show scroll bars. Check "Always" and your scroll bar will always be visible and easier to click and drag.